1. Field of the Invention
This invention pertains to the drying section of a papermaking machine, the drying section being comprised of several drying groups, a paper web, wherein the paper web, together with at least one endless dry sieve associated with each of the several drying groups, is alternately guided over reversing rolls and heated by drying cylinders, with the paper web being located between the dry sieves and the drying cylinders, and wherein within each drying group only one side of the paper web comes into contact with the drying cylinders, with the side being reversed between each drying group.
2. Discussion of the Background of the Invention and Material Information
U.S. Pat. No. 4,934,067 to Wedel sets forth a drying section for a papermaking machine in which the drying groups are so connected that the dry sieves of both successive groups are brought together at the transition region and come into contact with the web that is situated therebetween. At the same time, the dry sieves of both drying groups are guided over suction rolls that are arranged after the last and before the first drying cylinder.
A device or arrangement of the noted type permits no speed differential between the dryer groups and thus does not permit the possibility of adjusting the web tension. In addition, in the area of mutual contact, there is increased wear of the dry sieves during an eventual tearing of the web.
German Patent Publication DE-PS 4201107 suggests a solution therefor, in which there is a minimal distance between the sieve or screen bands. The transfer of the paper web from one sieve band to the other is also aided via blower unit.
However, the previously noted solution is still unsatisfactory due to the high costs associated with the transfer between the drying groups.
It is the task or object of this invention to produce a drying section having minimal costs associated with the transfer of the web between the drying groups; which permits control of the web tension via the speed differential between the drying groups; and has only a short free draw between the drying groups.